There are only a relatively few pediculicides which are commercially available today. The most popular pediculicidal toxicants are Lindane (gamma benzene hexachloride), Malathion [(S-1,2-dicarbethoxyethyl)-0,0-dimethyl phosphorodithioate], synergized pyrethrins and Cuprex (a combination of tetrahydronapthalene, copper oleate and acetone, the acetone not asserted to be active). Because of increased concern about the overall safety of some of the known ectoparasitic toxicants, the search for new, safe and effective pediculicides has intensified recently.
In addition to killing insects, a good ectoparasiticide should also destroy ova to avoid a resurgence of the infestation. Surviving ova may hatch days or weeks after the initial treatment. Lacking ovicidal activity, a pediculicide safe to the host usually must be re-applied until control is achieved.
It has now been found that those higher alcohols which have a logarithm of their partition coefficient between n-octanol and water of at least 0.61 exhibit pediculicidal and/or ovicidal activity. These alcohols are known materials and have been incorporated into many pharmaceutical and costmetic preparations. For example, cetyl alcohol constitutes 15% of a published hair groom gel and 61% of a floating bath oil, and lauryl or isocetyl or dodecyl alcohol constitute about 30% of a mineral oil gel. Cetyl alcohol and lauryl alcohol are also listed under the United States Food & Drug Administration's approved Synthetic Flavor Substituents and Adjuvants list (Z1 CFR 1.1.1164). Cetyl alcohol has been used in compositions applied to the skin (U.S. Pat. Nos. 3,226,295 and 3,943,234) and lauryl alcohol derivatives have been used in parasiticides (U.S. Pat. No. 2,030,093).
It is the object of this invention to provide new, safe and effective toxicants for lice and their ova, and mites. This and other objects of the invention will become apparent to those skilled in the art from the following detailed description.